This object is a cometary globule, nicknamed God’s Hand, located 1300 light years away in the constellation of Puppis at a declination of -47 degrees.
I posted an image of a similar sized and shaped northern hemisphere cometary globule last week, named
LBN 438.
Revision C of this post compares the 2 objects to the same scale.
I have always wanted to image CG4, from the first time I saw it years ago. But being at -47 degrees (transiting at 12 degrees above my southern horizon), I have never been successful at imaging it. I finally had a steady night and achieved tolerable, though not good, results.
The head of CG4 is about 6 arc-minutes in diameter, which corresponds to an actual width of 2.5 light years.
I love how CG4 appears to be in the process of devouring the edge-on galaxy ESO 257-19 (LEDA 21338). This galaxy is 120 million light years away, about 100,000 times further away than CG4. The galaxy is 100,000 light years in diameter.
As I described in more detail in my LBN 438 post last week, the red glowing color of the nebula is believed to not be HII. This object is thought to be an ERE (Extended Red Emission) object. ERE is a broad emission in the red band, peaking from 600 to 800 nm, thought to be the result of photoluminescence of dust by far-ultraviolet (FUV) photons, although its exact mechanism is still being debated in the scientific community.
The large galaxy at the bottom is NGC 2427, an 11.6 magnitude spiral galaxy located 36 million light years away. It is 60,000 light years in diameter.
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